JP2012129328A - Base material processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base material processing method capable of forming a thin film of uniform film thickness having excellent adhesion between a support base material and a base material using a temporarily fixing agent when temporarily fixing the base material onto the support base material and processing the base material and resultantly processing a base material with excellent accuracy.SOLUTION: A base material processing method comprises: a first step of supplying a temporarily fixing agent to one surface of a support base material 1 in a spin coating method and forming a sacrificial layer (thin film) 2 by drying the temporarily fixing agent; a second step of bonding a semiconductor wafer 3 and the support base material 1 via the sacrificial layer 2; a third step of processing a surface on the side opposite to a functional surface 31 of the semiconductor wafer 3; and a fourth step of detaching the semiconductor wafer 3 from the support base material 1 by thermally decomposing a resin component by heating the sacrificial layer 2. The support base material 1 is set so that an affinity to the temporarily fixing agent almost equals an affinity to the temporarily fixing agent of the functional surface 31.

Description

  The present invention relates to a base material processing method, and more particularly to a base material processing method in which a base material is temporarily fixed to a supporting base material using a temporary fixing agent.

  In order to perform processing such as polishing and etching on a semiconductor wafer, it is necessary to temporarily fix the semiconductor wafer on a base material for supporting the semiconductor wafer, and various methods have been proposed. For example, at present, a method of fixing a semiconductor wafer on a fixing film in which an adhesive layer is provided on a PET film as a base material is often used.

  In this method, when the grinding accuracy (about 1 μm) of a general back grinding machine used for grinding is combined with the thickness accuracy (about 5 μm) of a general back grinding (BG) tape for fixing a semiconductor wafer, There is a problem that the required thickness accuracy is exceeded and the thickness of the ground wafer varies.

  Also, when processing a semiconductor wafer used for through silicon vias, via holes and films are formed with a BG tape attached, and the temperature at that time reaches at least about 180 ° C., This will increase the adhesive strength of the BG tape. Further, the adhesive layer of the BG tape is eroded by the plating chemicals for film formation, and peeling may occur.

  In addition, since a fragile semiconductor wafer typified by a compound semiconductor may be damaged by mechanical grinding, it is thinned by etching. In this etching, there is no particular problem as long as the etching amount is for the purpose of removing stress. However, when etching is performed by several μm, the BG tape may be deteriorated by the etching chemical.

  On the other hand, in recent years, a method of fixing a semiconductor wafer to a support substrate having a smooth surface via a fixing material has been adopted.

  For example, in order to perform etching for the purpose of stress removal, it is necessary to heat to a high temperature, but PET film cannot withstand such a high temperature. In such a case, a method using a supporting substrate Is preferably applied.

  As a material for fixing the base material to the supporting base material, a fixing material that softens at a high temperature and facilitates the removal of the semiconductor wafer (see, for example, Patent Document 1) has been proposed.

  However, when a semiconductor wafer is fixed on a supporting base material using such a fixing material, when processing such as polishing or etching is performed on the semiconductor wafer, the supporting base material and the semiconductor wafer are interposed via the fixing material. If it is necessary to bond with excellent adhesion, and excellent adhesion cannot be obtained, peeling occurs at the interface between the support substrate and the fixing material or the interface between the semiconductor wafer and the fixing material. For example, when the semiconductor wafer is polished, there is a problem that the thickness of the semiconductor wafer varies.

  Such a problem is not limited to the processing of semiconductor wafers, but also occurs in various substrates that are processed in a state of being fixed to a supporting substrate via a fixing member.

Special table 2010-53385 gazette

  The object of the present invention is to form a thin film with excellent adhesion using a temporary fixing agent between the supporting base material and the base material when the base material is temporarily fixed on the supporting base material to process the base material. Thus, the thin film has a uniform film thickness, and as a result, a base material processing method capable of processing the base material with excellent accuracy is provided.

Such an object is achieved by the present invention described in the following (1) to (15).
(1) A thin film is prepared by supplying a temporary fixing agent composed of a resin composition containing a resin component that is melted or vaporized by heat decomposition by heating to one surface of a supporting substrate using a spin coating method, and then drying it. A first step of forming
A second step of bonding the substrate and the support substrate through the thin film;
A third step of processing the surface of the substrate opposite to the supporting substrate;
A fourth step of desorbing the base material from the support base material by thermally decomposing the resin component by heating the thin film;
At least a part of the one surface of the support base has an affinity for the temporary fixing agent that is substantially equal to the affinity of the surface of the base on the side of the support base for the temporary fixing agent. A substrate processing method characterized by being set.

  (2) In the above (1), the affinity of the one surface with respect to the temporary fixing agent is adjusted by at least one of the setting of the surface roughness Ra of the one surface and the surface treatment on the one surface. The processing method of the base material of description.

  (3) The one surface of the support substrate includes a first region and a second region having different affinity for the temporary fixing agent, and the first region or the second region is any one of the first region and the second region. The method for processing a substrate according to the above (1) or (2), wherein the affinity for the temporary fixing agent is substantially equal to the affinity for the temporary fixing agent on the surface of the substrate on the side of the supporting substrate. .

  (4) Said 1st area | region is an area | region along the edge part of said one surface of said support base material, and said 2nd area | region is an area | region inside said 1st area | region (3) The processing method of the base material as described in).

  (5) The substrate processing method according to (3) or (4), wherein the first region and the second region are continuous regions.

  (6) The substrate processing method according to any one of (1) to (5), wherein in the first step, the thin film is formed to have an average thickness of 50 to 100 μm.

  (7) The substrate processing method according to any one of (1) to (6), wherein in the first step, the thin film having a TMA softening point of less than 200 ° C. is formed.

  (8) Said (1) thru | or (7) which pressurizes with the pressure of 0.01-3 MPa in the said 2nd process in the direction which the said base material and the said support base material mutually approach in the state which interposed the said thin film. ) The processing method of the base material in any one of.

  (9) The substrate processing method according to any one of (1) to (8), wherein in the second step, the thin film is heated at a temperature of 100 to 300 ° C.

  (10) The substrate processing method according to (9), wherein the time for heating the thin film is 0.1 to 10 minutes.

  (11) The resin component is such that the thermal decomposition temperature is lowered by irradiation of the temporary fixing agent with active energy rays, and prior to the fourth step, the active energy rays are turned into the thin film. The processing method of the base material in any one of said (1) thru | or (10) to irradiate.

  (12) The resin component is such that the thermal decomposition temperature decreases in the presence of an acid or a base, and the resin composition further comprises an activator that generates an acid or a base by irradiation with the active energy ray. The processing method of the base material as described in said (11) to contain.

  (13) The substrate processing method according to (11) or (12), wherein the resin component is a polycarbonate resin.

  (14) The substrate processing method according to any one of (1) to (10), wherein the resin component is such that the temperature at which the thermal decomposition is performed does not decrease by irradiation of active energy rays to the temporary fixing agent.

  (15) The substrate processing method according to (14), wherein the resin component is a norbornene resin.

  According to the base material processing method of the present invention, the base material and the supporting base material are bonded with excellent adhesion through a thin film formed between the base material and the supporting base material using a temporary fixing agent. can do. Since such adhesion is obtained, the thin film has a uniform film thickness between the base material and the support base material, and as a result, it is possible to process the base material with high accuracy. There is an effect.

It is a longitudinal cross-sectional view for demonstrating 1st Embodiment of the manufacturing process which processes a semiconductor wafer to which the processing method of the base material of this invention was applied. It is a top view of the support base material used for 2nd Embodiment of the manufacturing process which processes a semiconductor wafer.

  Hereinafter, the processing method of the base material of this invention is demonstrated in detail based on suitable embodiment shown to an accompanying drawing.

  First, prior to explaining the processing method of the base material of the present invention, the temporary fixing agent used in the present invention will be described.

<Temporary fixative>
The temporary fixing agent is used to temporarily fix the base material to a supporting base material in order to process the base material, and to release the base material from the supporting base material by heating after processing the base material. And a resin composition containing a resin component that is thermally decomposed by heating.

  By using such a temporary fixing agent, the base material can be processed in a state where the base material is temporarily fixed to the supporting base material by a thin film formed using the temporary fixing agent, and further, by heating after processing. The base material can be detached from the supporting base material by melting or vaporizing the thin film.

  Hereinafter, each component which comprises the resin composition containing this resin component is demonstrated sequentially.

  The resin component has a function of fixing the base material to the supporting base material at the time of temporary fixing (processing the base material), and further thermally decomposes to lower the molecular weight by the heating of the temporary fixing agent. Since the bonding strength is reduced due to the melting or vaporization of the substrate, it has a function of allowing the substrate to be detached from the supporting substrate.

  The resin component is not particularly limited as long as it has the above-described function, but is not limited to polycarbonate resin, polyester resin, polyamide resin, polyimide resin, polyether resin, polyurethane resin, ( Examples thereof include a (meth) acrylate resin, a norbornene resin, and a polyolefin resin, and one or more of these can be used in combination. Among these, norbornene resins, polycarbonate resins, vinyl resins and (meth) acrylic resins are preferable, and norbornene resins or polycarbonate resins are particularly preferable. These are more suitably selected as the resin component because they exhibit the above functions more remarkably.

  Although it does not restrict | limit especially as a polycarbonate-type resin, Polypropylene carbonate resin, polyethylene carbonate resin, 1, 2- polybutylene carbonate resin, 1, 3- polybutylene carbonate resin, 1, 4- polybutylene carbonate resin, cis-2, 3-polybutylene carbonate resin, trans-2,3-polybutylene carbonate resin, α, β-polyisobutylene carbonate resin, α, γ-polyisobutylene carbonate resin, cis-1,2-polycyclobutylene carbonate resin, trans- 1,2-polycyclobutylene carbonate resin, cis-1,3-polycyclobutylene carbonate resin, trans-1,3-polycyclobutylene carbonate resin, polyhexene carbonate resin, polycyclopropyl Carbonate resin, polycyclohexene carbonate resin, 1,3-polycyclohexane carbonate resin, poly (methylcyclohexene carbonate) resin, poly (vinylcyclohexene carbonate) resin, polydihydronaphthalene carbonate resin, polyhexahydrostyrene carbonate resin, polycyclohexanepropylene Carbonate resin, polystyrene carbonate resin, poly (3-phenylpropylene carbonate) resin, poly (3-trimethylsilyloxypropylene carbonate) resin, poly (3-methacryloyloxypropylene carbonate) resin, polyperfluoropropylene carbonate resin, polynorbornene Carbonate resin, polynorbornane carbonate resin, exo-polynorbornene carbonate tree Fat, endo-polynorbornene carbonate resin, trans-polynorbornene carbonate resin, cis-polynorbornene carbonate resin can be used, and one or more of these can be used in combination.

  Examples of the polycarbonate resin include polypropylene carbonate / polycyclohexene carbonate copolymer, 1,3-polycyclohexane carbonate / polynorbornene carbonate copolymer, poly [(oxycarbonyloxy-1,1,4,4- Tetramethylbutane) -alt- (oxycarbonyloxy-5-norbornene-2-endo-3-endo-dimethane)] resin, poly [(oxycarbonyloxy-1,4-dimethylbutane) -alt- (oxycarbonyloxy -5-norbornene-2-endo-3-endo-dimethane)] resin, poly [(oxycarbonyloxy-1,1,4,4-tetramethylbutane) -alt- (oxycarbonyloxy-p-xylene)] Resin and poly [(oxycal Nyloxy-1,4-dimethylbutane) -alt- (oxycarbonyloxy-p-xylene)] resin, 1,3-polycyclohexane carbonate resin / exo-polynorbornene carbonate resin, 1,3-polycyclohexane carbonate resin / endo -Copolymers, such as polynorbornene carbonate resin, can also be used.

  Furthermore, as the polycarbonate-based resin, in addition to the above, a polycarbonate resin having at least two cyclic bodies in the carbonate constituent unit can also be used.

  The number of cyclic bodies may be two or more in the carbonate structural unit, but is preferably 2 to 5, more preferably 2 or 3, and further preferably 2. By including such a number of cyclic bodies as the carbonate constituent unit, the adhesion between the supporting base material and the base material becomes excellent. Moreover, when the temporary fixing agent is heated, the polycarbonate resin is thermally decomposed to have a low molecular weight, thereby melting.

  In addition, the plurality of cyclic bodies may have a linked polycyclic structure in which the vertices are connected to each other, but a condensed polycyclic structure in which the sides of each ring are connected to each other. It is preferable. Thereby, both heat resistance as a temporary fixing agent and shortening of the thermal decomposition time when this thing melts can be made compatible.

  Furthermore, it is preferable that each of the plurality of cyclic bodies is a 5-membered ring or a 6-membered ring. Thereby, since the planarity of a carbonate structural unit is maintained, the solubility with respect to a solvent can be stabilized more.

  Such a plurality of cyclic bodies are preferably alicyclic compounds. When each cyclic body is an alicyclic compound, the effects as described above are more remarkably exhibited.

  In consideration of these, in the polycarbonate resin, as the carbonate structural unit, for example, a structure represented by the following chemical formula (1X) is a particularly preferable structure.

  In addition, the polycarbonate-type resin which has a carbonate structural unit represented by the said Chemical formula (1X) can be obtained by the polycondensation reaction of decalin diol and carbonic acid diester like diphenyl carbonate.

  In the carbonate structural unit represented by the chemical formula (1X), those derived from the carbon atom linked to the hydroxyl group of decalin diol are each decalin (that is, two cyclic bodies forming a condensed polycyclic structure). It is preferable that three or more atoms intervene between the carbon atoms that are bonded to the carbon atoms constituting and bonded to these hydroxyl groups. Thereby, the decomposability | degradability of polycarbonate-type resin can be controlled, As a result, heat resistance as a temporary fixing agent and shortening of the thermal decomposition time when this thing fuse | melts can be made compatible. Furthermore, the solubility with respect to a solvent can be stabilized more.

  Examples of such a carbonate structural unit include those represented by the following chemical formulas (1A) and (1B).

  Further, the plurality of cyclic bodies may be alicyclic compounds or may be heteroalicyclic compounds. Even when each cyclic body is a heteroalicyclic compound, the effects as described above are more remarkably exhibited.

  In this case, in the polycarbonate resin, as the carbonate structural unit, for example, one represented by the following chemical formula (2X) is a particularly preferable structure.

  In addition, the polycarbonate-type resin which has a carbonate structural unit represented by the said Chemical formula (2X) can be obtained by the polycondensation reaction of ether diol represented by the following Chemical formula (2a), and carbonic acid diester like diphenyl carbonate.

  In the carbonate structural unit represented by the chemical formula (2X), the carbon atom derived from the hydroxyl group of the cyclic ether diol represented by the chemical formula (2a) forms the cyclic ether (that is, a condensed polycyclic structure). It is preferable that three or more atoms are interposed between these carbon atoms and bonded to the carbon atoms constituting the two cyclic bodies. Thereby, both heat resistance as a temporary fixing agent and shortening of the thermal decomposition time when this thing melts can be made compatible. Furthermore, the solubility with respect to a solvent can be stabilized more.

  Examples of such a carbonate structural unit include those of the 1,4: 3,6-dianhydro-D-sorbitol (isosorbide) type represented by the following chemical formula (2A), and those represented by the following chemical formula (2B). 4: 3,6-dianhydro-D-mannitol (isomannide) type.

  The weight-average molecular weight (Mw) of the polycarbonate-based resin is preferably 1,000 to 1,000,000, and more preferably 5,000 to 800,000. By setting the weight average molecular weight to the above lower limit or more, it is possible to obtain the effect of improving the wettability with respect to the support substrate and further improving the film formability. Moreover, by setting it as the said upper limit or less, the effect that the solubility with respect to various solvents and also the fall of the melt viscosity by the heating of a temporary fixing agent are recognized more notably can be acquired.

  In addition, the polymerization method of polycarbonate-type resin is not necessarily limited, For example, well-known polymerization methods, such as the phosgene method (solvent method) or the transesterification method (melting method), can be used.

  Although it does not specifically limit as norbornene-type resin, For example, what contains the structural unit shown by the following general formula (1Y) can be mentioned.

In the formula (1Y), R ^{1 to} R ⁴ are each hydrogen, a linear or branched alkyl group having 1 to 20 carbon atoms, an aromatic group, an alicyclic group, a glycidyl ether group, the following substituent (2Y ) Moreover, m is an integer of 0-4.

In the formula (2Y), R ⁵ is hydrogen, a methyl group, or an ethyl group, and R ⁶ , R ^7, and R ⁸ are each a linear or branched alkyl group having 1 to 20 carbon atoms, linear, or Branched alkoxy group having 1 to 20 carbon atoms, linear or branched alkylcarbonyloxy group having 1 to 20 carbon atoms, linear or branched alkyl peroxy group having 1 to 20 carbon atoms, substituted or unsubstituted It is any of aryloxy groups having 6 to 20 carbon atoms. N is an integer of 0-5.

  The linear or branched alkyl group having 1 to 20 carbon atoms is not particularly limited, but is a methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group. , Nonyl group, decyl group and the like.

  Among these, compatibility with various components constituting the temporary fixing agent (resin composition) and solubility in various solvents, and a butyl group having excellent mechanical properties when temporarily fixing the base material and the supporting base material, A decyl group is preferred.

  The aromatic group is not particularly limited, and examples thereof include a phenyl group, a phenethyl group, and a naphthyl group. Among these, the mechanical properties when the substrate and the supporting substrate are temporarily fixed are excellent. A phenethyl group and a naphthyl group are preferred.

  The alicyclic group is not particularly limited, but is a cyclohexyl group, norbornenyl group, dihydrodicyclopentadiethyl group, tetracyclododecyl group, methyltetracyclododecyl group, tetracyclododecadiethyl group, dimethyltetracyclododecyl group. And alicyclic groups such as trimer of ethyl group, ethyltetracyclododecyl group, ethylidenyltetracyclododecyl group, phenyltetracyclododecyl group, and cyclopentadiethyl group.

  Among these, a cyclohexyl group and a norbornenyl group, which are excellent in mechanical properties when the base material and the supporting base material are temporarily fixed, and further excellent in thermal decomposability when the temporary fixing agent is heated, are preferable.

R ⁵ in the substituent (2Y) is not particularly limited as long as it is hydrogen, a methyl group, or an ethyl group, but a hydrogen atom that is excellent in thermal decomposability during heating of the temporary fixing agent is preferable.

R ⁶ , R ⁷ and R ⁸ in the substituent (2Y) are each a linear or branched alkyl group having 1 to 20 carbon atoms, a linear or branched alkoxy group having 1 to 20 carbon atoms, Either a linear or branched alkylcarbonyloxy group having 1 to 20 carbon atoms, a linear or branched alkylperoxy group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms If so, there is no particular limitation.

  Examples of such substituents include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, acetoxy group, propoxy group, butoxy group, methylperoxy group, isopropylperoxy group, t-butylperoxy group, phenoxy group. , A hydroxyphenoxy group, a naphthyloxy group, a phenoxy group, a hydroxyphenoxy group, a naphthyloxy group, and the like. An ethoxy group and a propoxy group are preferable.

  M in the general formula (1Y) is an integer of 0 to 4, and is not particularly limited, but 0 or 1 is preferable. When m is 0 or 1, the structural unit represented by the general formula (1Y) can be represented by the following general formula (3Y) or (4Y).

In the formulas (3Y) and (4Y), R ^{1 to} R ⁴ are each hydrogen, a linear or branched alkyl group having 1 to 20 carbon atoms, an aromatic group, an alicyclic group, a glycidyl ether group, One of the substituents (2Y).

  N in the substituent (2Y) is an integer of 0 to 5, and is not particularly limited, but n is preferably 0. When n is 0, the silyl group is directly bonded to the polycyclic ring via a silicon-carbon bond, so that both the thermal decomposability of the temporary fixing agent and the mechanical properties during processing of the substrate can be achieved.

  The structural unit represented by the general formula (1Y) is not particularly limited, but norbornene, 5-methylnorbornene, 5-ethylnorbornene, 5-propylnorbornene, 5-butylnorbornene, 5-pentylnorbornene, 5 -Hexyl norbornene, 5-heptyl norbornene, 5-octyl norbornene, 5-nonyl norbornene, 5-decyl norbornene, 5-phenethyl norbornene, 5-triethoxysilyl norbornene, 5-trimethylsilyl norbornene, 5-trimethoxysilyl norbornene, 5 It can be obtained by polymerizing norbornene-based monomers such as methyldimethoxysisilylnorbornene, 5-dimethylmethoxynorbornene, and 5-glycidyloxymethylnorbornene.

  When the norbornene monomer is polymerized, it may be polymerized with a single norbornene monomer or a plurality of norbornene monomers. Among these norbornene-based monomers, 5-butylnorbornene, 5-decylnorbornene, 5-phenethylnorbornene, 5-triethoxysilylnorbornene, and 5-glycidyloxy are excellent in mechanical properties when the substrate and the supporting substrate are temporarily fixed. Methylnorbornene is preferred.

  The norbornene-based resin is not particularly limited, and may be formed of a single structural unit represented by the general formula (1Y) or may be formed of a plurality of structural units.

  More specifically, the norbornene-based resin is polynorbornene, polymethylnorbornene, polyethylnorbornene, polypropylnorbornene, polybutylnorbornene, polypentylnorbornene, polyhexylnorbornene, polyheptylnorbornene, polyoctylnorbornene, polynonyl. Single polymer such as norbornene, polydecyl norbornene, polyphenethyl norbornene, polytriethoxysilyl norbornene, polytrimethylsilyl norbornene, polytrimethoxysilyl norbornene, polymethyldimethoxysisilyl norbornene, polydimethylmethoxynorbornene, polyglycidyloxymethyl norbornene, norbornene -Triethoxysilyl norbornene copolymer, norbornene-glycidyloxymethyl ester Borene copolymer, butylnorbornene-triethoxysilylnorbornene copolymer, decylnorbornene-triethoxysilylnorbornene copolymer, butylnorbornene-glycidyloxymethylnorbornene copolymer, decylnorbornene-glycidyloxymethylnorbornene copolymer, decyl Examples thereof include copolymers such as norbornene-butylnorbornene-phenethylnorbornene-glycidyloxymethylnorbornene copolymer.

  Among these, polybutylnorbornene, polydecylnorbornene, polytriethoxysilylnorbornene, polyglycidyloxymethylnorbornene-butylnorbornene-triethoxysilylnorbornene copolymer having excellent mechanical properties when the substrate and the supporting substrate are temporarily fixed Polymer, decylnorbornene-triethoxysilylnorbornene copolymer, butylnorbornene-glycidyloxymethylnorbornene copolymer, decylnorbornene-glycidyloxymethylnorbornene copolymer, decylnorbornene-butylnorbornene-phenethylnorbornene-glycidyloxymethylnorbornene copolymer Coalescence is preferred.

  The norbornene-based resin having the structural unit represented by the general formula (1Y) is not particularly limited, but ring-opening metathesis polymerization (hereinafter also referred to as ROMP), a combination of ROMP and hydrogenation reaction. It can be synthesized by polymerization with radicals or cations.

  More specifically, the norbornene-based resin having the structural unit represented by the general formula (1Y) is obtained by using, for example, a catalyst containing a palladium ion source, a catalyst containing nickel and platinum, a radical initiator, or the like. Can be synthesized.

  Moreover, it is preferable to mix | blend the resin component in the ratio of 10 wt%-100 wt% of the whole quantity which comprises a resin composition (when a solvent is included, the whole quantity except a solvent). More preferably, it is blended at a ratio of 50 wt% or more, particularly 80 wt% to 100 wt%. By making it 10 wt% or more, particularly 80 wt% or more, there is an effect that the residue after thermally decomposing the temporary fixing agent can be reduced. Moreover, there exists an effect that a temporary fixing agent can be thermally decomposed in a short time by increasing the resin component in a resin composition.

  The resin components as described above are classified into those in which the temperature for thermal decomposition decreases in the presence of an acid or a base and those in which the temperature for thermal decomposition does not decrease.

  Specifically, examples of the resin component that lowers the thermal decomposition temperature in the presence of an acid or base include, for example, polycarbonate resins, polyester resins, polyamide resins, polyether resins, polyurethane resins, (meth) An acrylate resin etc. are mentioned, Among these, it can use combining 1 type (s) or 2 or more types. Among these, it is preferable to use a polycarbonate-based resin from the viewpoint that a decrease in the temperature for thermal decomposition is more remarkably recognized. In particular, polypropylene carbonate, 1,4-polybutylene carbonate, 1,3-polycyclohexane carbonate / A polynorbornene carbonate copolymer is preferred.

  In addition, examples of the resin component that does not decrease the thermal decomposition temperature in the presence of an acid or a base include norbornene-based resins and polyolefin-based resins, and one or more of these are used in combination. be able to.

  Therefore, when a resin component whose thermal decomposition temperature is reduced in the presence of an acid or a base is selected, an acid or a base is generated in the resin composition by irradiation with active energy rays on the temporary fixing agent. By setting it as the structure containing an activator, the temperature which thermally decomposes a resin component by irradiation of the active energy ray to a temporary fixing agent shall fall.

  Therefore, the temporary fixing agent (resin composition) contains a resin component whose temperature for thermal decomposition is reduced and an active agent that generates an acid or a base by irradiation of active energy rays to the temporary fixing agent. Because the temperature at which the resin component is thermally decomposed by irradiation with active energy rays decreases, the temporary fixing agent after heating with active energy rays can be more easily detached from the supporting substrate. An effect is obtained.

  When the resin component is selected so that the temperature at which pyrolysis does not decrease in the presence of an acid or base, the acid or base is added to the resin composition by irradiation with active energy rays. Even if the generated activator is added, naturally, the temperature at which the resin component is thermally decomposed does not change even when the temporary fixing agent is irradiated with active energy rays.

  Hereinafter, the activator contained in the resin composition will be described when a resin component having a reduced thermal decomposition temperature in the presence of an acid or a base is selected.

(Active agent)
As described above, the activator generates an active species such as an acid or a base when energy is applied by irradiation with an active energy ray, and the action of the active species causes thermal decomposition of the resin component. It has a function to lower the temperature.

  The activator is not particularly limited, and examples thereof include a photoacid generator that generates an acid upon irradiation with active energy rays, and a photobase generator that generates a base upon irradiation with active energy rays.

  The photoacid generator is not particularly limited, and examples thereof include tetrakis (pentafluorophenyl) borate-4-methylphenyl [4- (1-methylethyl) phenyl] iodonium (DPI-TPFPB), tris (4-t- Butylphenyl) sulfonium tetrakis- (pentafluorophenyl) borate (TTBPS-TPFPB), tris (4-t-butylphenyl) sulfonium hexafluorophosphate (TTBPS-HFP), triphenylsulfonium triflate (TPS-Tf), bis ( 4-tert-butylphenyl) iodonium triflate (DTBPI-Tf), triazine (TAZ-101), triphenylsulfonium hexafluoroantimonate (TPS-103), triphenylsulfonium bis (par Fluoromethanesulfonyl) imide (TPS-N1), di- (pt-butyl) phenyliodonium, bis (perfluoromethanesulfonyl) imide (DTBPI-N1), triphenylsulfonium, tris (perfluoromethanesulfonyl) methide ( TPS-C1), di- (pt-butylphenyl) iodonium tris (perfluoromethanesulfonyl) methide (DTBPI-C1), and the like, and one or a combination of two or more of these can be used. . Among these, tetrakis (pentafluorophenyl) borate-4-methylphenyl [4- (1-methylethyl) phenyl] iodonium (DPI-), particularly from the viewpoint that the melt viscosity of the resin component can be efficiently lowered. TPFPB) is preferred.

  The photobase generator is not particularly limited, and examples thereof include 5-benzyl-1,5-diazabicyclo (4.3.0) nonane, 1- (2-nitrobenzoylcarbamoyl) imidazole, and the like. 1 type or 2 types or more can be used in combination. Among these, 5-benzyl-1,5-diazabicyclo (4.3.0) nonane and derivatives thereof are particularly preferable from the viewpoint that the melt viscosity of the resin component can be efficiently lowered.

  The activator is preferably about 0.01 to 50% by weight, and more preferably about 0.1 to 30% by weight, based on the total amount of the resin composition (temporary fixing agent). By setting it within such a range, it becomes possible to stably lower the melt viscosity of the resin component within the target range.

  By irradiating active energy rays by adding such an activator, an active species such as an acid or a base is generated, and the action of the active species lowers the thermal decomposition temperature of the main chain of the resin component. It is inferred that a structure is formed, and as a result, the temperature at which the resin component is thermally decomposed decreases.

Here, the mechanism by which the thermal decomposition temperature is lowered when a polypropylene carbonate resin, which is a polycarbonate resin, is used as the resin component and a photoacid generator is used as the activator will be described. As shown by the following formula (1Z), first, H ⁺ derived from the photoacid generator protonates the carbonyl oxygen of the polypropylene carbonate resin, and further transitions the polar transition state to an unstable tautomeric intermediate [A ] And [B]. Next, the thermal decomposition temperature of the intermediate [A] is lowered because fragmentation as acetone and CO ₂ occurs. Further, the intermediate [B] generates propylene carbonate, and propylene carbonate forms a thermal ring-closing structure that is fragmented as CO ₂ and propylene oxide, so that the thermal decomposition temperature is lowered.

(Sensitizer)
Further, when the temporary fixing agent contains an active agent, it may contain a sensitizer that is a component having a function of expressing or increasing the reactivity of the active agent with respect to an active energy ray of a specific wavelength together with the active agent. good.

  The sensitizer is not particularly limited. For example, anthracene, phenanthrene, chrysene, benzpyrene, fluoranthene, rubrene, pyrene, xanthone, indanthrene, thioxanthen-9-one, 2-isopropyl-9H- Examples include thioxanthen-9-one, 4-isopropyl-9H-thioxanthen-9-one, 1-chloro-4-propoxythioxanthone, and mixtures thereof.

  The content of such a sensitizer is preferably 100 parts by weight or less with respect to 100 parts by weight of the total amount of the activator such as the photoacid generator and the photo radical initiator, and is 20 parts by weight or less. More preferably.

  In the resin composition as described above, the resin component may be any of those whose thermal decomposition temperature decreases in the presence of an acid or a base and those whose thermal decomposition temperature does not decrease. Other components as shown may be included.

(Antioxidant)
That is, the resin composition (temporary fixing agent) may contain an antioxidant.

  This antioxidant has a function of preventing acid generation and natural oxidation in the resin composition (temporary fixing agent).

  The antioxidant is not particularly limited. For example, “Ciba IRGANOX (registered trademark) 1076” and “Ciba IRGAFOS (registered trademark) 168” manufactured by Ciba Fine Chemicals are preferably used.

  Other antioxidants include, for example, “Ciba Irganox 129”, “Ciba Irganox 1330”, “Ciba Irganox 1010”, “Ciba Cyanox (registered trademark) 1790”, “Ciba Irganox 3114 C” Can also be used.

  The content of the antioxidant is preferably 0.1 to 10 parts by weight, and more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the resin component described above.

(Additive)
Moreover, the resin composition (temporary fixing agent) may contain additives such as acid scavengers, acrylic, silicone, fluorine, and vinyl leveling agents, silane coupling agents, and diluents as necessary. .

  The silane coupling agent is not particularly limited. For example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p -Styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxy Silane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltri Ethoxysilane 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxypropyl) Examples thereof include tetrasulfide and 3-isocyanatopropyltriethoxysilane, and among these, one kind or two or more kinds can be used in combination.

  By including a silane coupling agent in the resin composition (temporary fixing agent), it is possible to improve the adhesion between the base material and the support base material.

  The diluent is not particularly limited, and examples thereof include cycloether compounds such as cyclohexene oxide and α-pinene oxide, aromatic cycloethers such as [methylenebis (4,1-phenyleneoxymethylene)] bisoxirane, 1, Examples thereof include cycloaliphatic vinyl ether compounds such as 4-cyclohexanedimethanol divinyl ether, and one or more of these can be used in combination.

  When the resin composition (temporary fixing agent) contains a diluent, the fluidity of the temporary fixing agent can be improved, and the wettability of the temporary fixing agent with respect to the support base material is improved in the sacrificial layer forming step described later. It becomes possible.

(solvent)
Moreover, the resin composition (temporary fixing agent) may contain a solvent.

  By setting the resin composition to include a solvent, it is possible to easily adjust the viscosity and the like of the resin composition.

  The solvent is not particularly limited. For example, hydrocarbons such as mesitylene, decalin, and mineral spirits, aromatic hydrocarbons such as toluene, xylene, and trimethylbenzene, anisole, propylene glycol monomethyl ether, Alcohols / ethers such as propylene glycol methyl ether, diethylene glycol monoethyl ether, diglyme, ethylene carbonate, ethyl acetate, N-butyl acetate, ethyl lactate, ethyl 3-ethoxypropionate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate , Esters / lactones such as propylene carbonate and γ-butyrolactone, keto such as cyclopentanone, cyclohexanone, methyl isobutyl ketone, 2-heptanone S, N- methyl-2-amide / lactam such as pyrrolidone, and the like, can be used singly or in combination of two or more of them. Thereby, it becomes easy to adjust the viscosity of the temporary fixing agent, and it becomes easy to form a sacrificial layer (thin film) composed of the temporary fixing agent on the support base material.

  Although content of the said solvent is not specifically limited, It is preferable that it is 5-98 weight% with respect to the whole quantity of a resin composition (temporary fixing agent), and it is more preferable that it is 10-95 weight%.

<Method for Manufacturing Semiconductor Device>
The temporary fixing agent as described above is applied to a method for manufacturing a semiconductor device, for example.

  That is, the substrate processing method of the present invention using a temporary fixing agent is applied to the processing of a semiconductor wafer in the method for manufacturing a semiconductor device.

  In this semiconductor wafer (base material) processing method, the above-described temporary fixing agent is supplied to the upper surface (one surface) of the semiconductor wafer using a spin coating method and then dried to form a sacrificial layer (thin film). A second step of bonding the supporting base material and the semiconductor wafer through the sacrificial layer, a third step of processing the upper surface (the surface opposite to the supporting base material) of the semiconductor wafer, and sacrificing A fourth step of desorbing the semiconductor wafer from the support base by heating the layer to thermally decompose the resin component. In the method for processing a semiconductor wafer having such a configuration, in the present invention, at least a part of the one surface of the support base material has an affinity for the temporary fixing agent, the surface of the base material on the support base material side. Is set to be substantially equal to the affinity for the temporary fixing agent.

<< First Embodiment >>
Hereinafter, a first embodiment of the substrate processing method of the present invention will be described.

  FIG. 1 is a longitudinal sectional view for explaining a first embodiment of a processing step for processing a semiconductor wafer, to which the substrate processing method of the present invention is applied. In the following description, in FIG. 1, the upper side is “upper” and the lower side is “lower”.

Hereinafter, each of these steps will be described sequentially.
(Sacrificial layer formation process)
First, a support base material 1 is prepared, and a sacrificial layer 2 is formed on the support base material 1 by supplying a temporary fixing agent using a spin coating method and drying the support base material 1 as shown in FIG. (First step; see FIG. 1B).

  In the present embodiment, the affinity for the temporary fixing agent is substantially equal to the affinity for the temporary fixing agent of the functional surface 31 of the semiconductor wafer 3 to be described later over almost the entire upper surface (one surface).

  Thus, the affinity for the temporary fixing agent on the upper surface of the support substrate 1 is set to be substantially equal to the affinity for the temporary fixing agent of the functional surface 31, so that the semiconductor wafer 3 and the support group are interposed via the sacrificial layer 2. The material 1 can be bonded with excellent adhesion, and the sacrificial layer 2 can have a uniform film thickness. This will be described in detail later.

  There are various methods for making the affinity of the upper surface of the support substrate 1 and the functional surface 31 of the semiconductor wafer 3 substantially equal to the temporary fixing agent. The surface roughness Ra of the upper surface of the support substrate 1 It is preferable to be based on at least one of setting and surface treatment on the upper surface of the support substrate 1. According to this method, the affinity can be easily equalized.

  The surface roughness Ra of the upper surface of the support substrate 1 may be set as appropriate according to the surface properties formed by the conductive material, such as wiring or bumps, formed on the functional surface 31 of the semiconductor wafer 3, and in particular. Although not limited, specifically, it is preferably about 0.001 to 10 μm, and more preferably about 0.01 to 5 μm.

  Further, the surface treatment for improving the hydrophilicity is not particularly limited, but a treatment for introducing a hydroxyl group into the upper surface of the support substrate 1 is preferable. Examples of such treatment include ultraviolet irradiation, plasma irradiation, electron beam irradiation, corona discharge treatment, and the like, and one or more of these can be used in combination.

  On the other hand, the surface treatment for improving the liquid repellency is not particularly limited, but a treatment for imparting a liquid repellency compound, a fluorine resin, or the like to the upper surface of the support substrate 1 is preferable.

  Examples of the liquid repellent compound include a coupling agent or a surfactant having a liquid repellent functional group such as a fluoroalkyl group, an alkyl group, a vinyl group, an epoxy group, a styryl group, and a methacryloxy group.

  As the coupling agent, for example, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent, a zirconium coupling agent, an organic phosphate coupling agent, a silyl peroxide coupling agent, or the like is used. be able to.

  Moreover, as surfactant, the various surfactant etc. which have the said functional group at the terminal can be used, for example.

  On the other hand, examples of the fluorine resin material include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), and perfluoroethylene. -Propene copolymer (FEP), ethylene-chlorotrifluoroethylene copolymer (ECTFE), etc. can be used.

  Moreover, it is preferable that the viscosity (25 degreeC) of the temporary fixing agent supplied to the upper surface of the support base material 1 using a spin coat method is about 500-100,000 mPa * s, and 1,000-50,000 mPa. -It is more preferable that it is about s, and it is further more preferable that it is about 2,000-40,000 mPa * s.

  The viscosity (25 ° C.) can be measured by using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., viscometer TVE-22 type) at a cone temperature of 25 ° C. after 3 minutes.

  Furthermore, it is preferable to set the rotation speed of the support substrate 1 for supplying the temporary fixing agent to about 300 to 3,000 rpm, more preferably about 500 to 2,000 rpm, and 600 to 1,800 rpm. More preferably, the degree is set.

  By setting the viscosity of the temporary fixing agent and the number of rotations of the support base material 1 within the above ranges, a uniform thickness is sacrificed on the upper surface of the support base material 1 having the above-described surface properties. The layer 2 can be formed relatively easily.

  Moreover, when the viscosity (25 degreeC) of a temporary fixing agent is set to A [mPa * s], and the rotation speed of the support base material 1 is set to B [rpm], A / B is 0.13-330. Preferably, it is 0.5-100. Thereby, the sacrificial layer 2 can be formed with a particularly uniform and flat thickness.

  Furthermore, the TMA (Thermal Mechanical Analysis) softening point of the deposited sacrificial layer 2 is not particularly limited, but is preferably less than 200 ° C, more preferably about 50 to 180 ° C. Thereby, in the next process (bonding process), when heated, at least the surface can be brought into a molten state.

  The TMA softening point is measured by a thermomechanical measurement device (TMA), and the temperature of the measurement object is increased while applying a constant load at a constant temperature increase rate, and the phase of the measurement object is determined. It is obtained by observation. In this specification, the temperature at which the phase of the sacrificial layer 2 starts to change is defined as the TMA softening point. Specifically, the TMA softening point is, for example, a thermomechanical measuring device (TA Instruments Inc.). The phase changes when a load of 10 g is applied to a 1 mmφ quartz glass pin (needle) when the measurement temperature range is 25 to 200 ° C. and the heating rate is 5 ° C./min. It can be determined by measuring the temperature at which it begins.

  Further, the supporting substrate 1 is not particularly limited as long as it has a strength that can support the semiconductor wafer 3, but it is preferable that the supporting substrate 1 has optical transparency. As a result, when a resin component whose thermal decomposition temperature is reduced by irradiation with active energy rays is used as the resin component, the active energy rays are transmitted through the sacrificial layer 2 from the support base material 1 side. Irradiation can be ensured.

  As the support substrate 1 having optical transparency, for example, glass materials such as quartz glass and soda glass, and resin materials such as polyethylene terephthalate, polyethylene naphthalate, polypropylene, cycloolefin polymer, polyamide, and polycarbonate are mainly used. The board | substrate comprised as a material is mentioned.

  The sacrificial layer 2 is preferably formed to have an average thickness of about 50 to 100 μm, more preferably about 70 to 90 μm. If the sacrificial layer 2 is formed with such a thickness, it is possible to prevent the sacrificial layer 2 from functioning as a cushion and damaging the circuit of the functional surface 31 in a subsequent processing step.

(Lamination process)
Next, as shown in FIG. 1C, the semiconductor wafer (base material) 3 is placed on the surface on which the sacrificial layer 2 is provided on the support base material 1 so that the functional surface 31 is on the sacrificial layer 2 side. In this state, the semiconductor wafer 3 is bonded to the support base material 1 via the sacrificial layer 2 by thermocompression bonding (second step).

  Bonding by thermocompression bonding can be easily performed using, for example, an apparatus such as a vacuum press machine or a wafer bonder.

  Here, with the sacrificial layer 2 interposed, the pressure when the semiconductor wafer 3 and the support base 1 are pressed in a direction approaching each other is not particularly limited, but is preferably about 0.01 to 3 MPa. More preferably, it is about 0.05 to 2 MPa.

  At this time, the temperature for heating the sacrificial layer 2 is not particularly limited, but is preferably about 100 to 300 ° C, more preferably about 120 to 250 ° C.

  Furthermore, although the time to pressurize and heat is not specifically limited, It is preferable that it is about 0.1 to 10 minutes, and it is more preferable that it is about 0.5 to 5 minutes.

  By thermocompression bonding the sacrificial layer 2 to the functional surface 31 under such conditions, at least the surface of the sacrificial layer 2 is in contact with the functional surface 31 in a molten state. Here, since the functional surface 31 of the semiconductor wafer 3 is formed with wirings, bumps, and the like made of a conductive material, the functional surface 31 is formed of an uneven surface. As described above, the functional surface 31 is constituted by an uneven surface, but since the sacrificial layer 2 is at least in a molten state, when the sacrificial layer 2 comes into contact with the functional surface 31, the uneven surface is followed. Since the sacrificial layer 2 is embedded in the functional surface 31, the semiconductor wafer 3 and the support base material 1 are interposed via the sacrificial layer 2 in a state where the semiconductor wafer 3 and the support base material 1 are maintained at a constant interval. Are joined.

  At this time, if the affinity of the upper surface of the support substrate 1 for the temporary fixing agent and the affinity of the functional surface 31 of the semiconductor wafer 3 for the temporary fixing agent are different, in this step, via the sacrificial layer 2, When the semiconductor wafer 3 is fixed on the support substrate 1, sufficient adhesion cannot be obtained at either the interface between the support substrate 1 and the sacrificial layer 2 or the interface between the semiconductor wafer 3 and the sacrificial layer 2. There is a problem that peeling occurs due to this. Further, even if peeling does not occur, if the adhesion is insufficient, the sacrificial layer 2 undulates between the substrates when the semiconductor wafer 3 is bonded in this step, and as a result, the film of the sacrificial layer 2 There is also a problem that the thickness becomes uneven.

  On the other hand, in this embodiment, as described above, the affinity of the upper surface of the support substrate 1 for the temporary fixing agent is substantially equal to the affinity of the functional surface 31 of the semiconductor wafer 3 for the temporary fixing agent. . Therefore, the sacrificial layer 2 exhibits excellent adhesion to both of the interfaces of the support substrate 1 and the semiconductor wafer 3, so that it is possible to prevent or suppress the occurrence of peeling at the interface while accurately supporting or A sacrificial layer 2 having a uniform film thickness is formed between the material 1 and the semiconductor wafer 3.

  When the TMA softening point of the sacrificial layer 2 is within the range described in the sacrificial layer forming step, the sacrificial layer 2 is thermocompression bonded to the functional surface 31 under the pressurizing condition and temperature condition described above. It becomes possible to bond the semiconductor wafer 3 and the support base 1 via the sacrificial layer 2 with better adhesion.

(Processing process)
Next, a surface (back surface) opposite to the functional surface 31 of the semiconductor wafer 3 fixed on the support substrate 1 through the sacrificial layer 2 is processed (third step).

  The processing of the semiconductor wafer 3 is not particularly limited. For example, in addition to grinding and polishing the back surface of the semiconductor wafer 3 as shown in FIG. 1D, for forming a via hole in the semiconductor wafer 3 and for stress release. Etching of the back surface of the semiconductor wafer 3, lithography, coating of a thin film on the back surface of the semiconductor wafer 3, vapor deposition, and the like can be given.

  Here, in the present invention, as described in the sacrificial layer forming step and the bonding step, the semiconductor wafer 3 is bonded to the support substrate 1 through the sacrificial layer 2 with excellent adhesion. In this step, the occurrence of peeling at the interface between the support base 1 and the semiconductor wafer 3 of the sacrificial layer 2 is accurately prevented or suppressed. Further, the sacrificial layer 2 is formed with a uniform film thickness between the support base 1 and the semiconductor wafer 3. As a result, the upper surface (back surface) of the semiconductor wafer 3 can be ground and polished without causing variations in thickness.

  Furthermore, in the present invention, since the sacrificial layer 2 is formed with a uniform film thickness, the semiconductor wafer 3 is interposed via the sacrificial layer 2 in a state in which the semiconductor wafer 3 and the support base 1 are maintained at a constant interval. Bonded to the support substrate 1. Therefore, also from such a viewpoint, the upper surface can be ground and polished without variation in thickness.

(Desorption process)
Next, as shown in FIG. 1E, the sacrificial layer 2 is heated at a second temperature higher than the first temperature, whereby the resin component is thermally decomposed to lower the molecular weight, whereby the sacrificial layer 2 is obtained. After being melted or vaporized, the semiconductor wafer 3 is detached from the support substrate 1 (fourth step).

  The temperature at which the sacrificial layer 2 is heated is set to a temperature at which the resin component is thermally decomposed, and a temperature at which the deterioration / deterioration of the semiconductor wafer 3 is prevented. Specifically, the temperature is preferably about 100 to 500 ° C. Preferably, it is set to about 120 to 450 ° C.

  Here, in the present specification, desorption means an operation of peeling the semiconductor wafer 3 from the support base material 1, regardless of whether the sacrificial layer 2 is in a molten state or vaporized, for example, The operation includes a method of detaching the semiconductor wafer 3 in a direction perpendicular to the surface of the support substrate 1, a method of detaching the semiconductor wafer 3 by sliding in a horizontal direction relative to the surface of the support substrate 1, As shown in FIG. 1 (f), a method of detaching the semiconductor wafer 3 by lifting it from the support base 1 from one end side of the semiconductor wafer 3 and the like can be mentioned.

  In addition, when the sacrificial layer 2 is vaporized through the heating step, the sacrificial layer 2 is removed from between the semiconductor wafer 3 and the support base 1, so that the sacrificial layer 2 is removed from the support base 1. The semiconductor wafer 3 can be detached more easily.

(Washing process)
Next, in the desorption step, when the sacrificial layer 2 is in a molten state by heating the sacrificial layer 2 or when a part of the vaporized sacrificial layer 2 remains, if necessary, The sacrificial layer 2 remaining on the functional surface 31 of the semiconductor wafer 3 is cleaned.
That is, the residue of the sacrificial layer 2 remaining on the functional surface 31 is removed.

  A method for removing this residue is not particularly limited, and examples thereof include plasma treatment, chemical immersion treatment, polishing treatment, and heat treatment.

  In the present embodiment, the sacrificial layer 2 is formed on the support substrate 1 in the sacrificial layer formation step. However, the present invention is not limited to this, and the sacrificial layer 2 is formed on both the support substrate 1 and the semiconductor wafer 3. Alternatively, the sacrificial layer 2 may be selectively formed on the semiconductor wafer 3 without forming the sacrificial layer 2 on the support substrate 1.

As described above, the back surface of the semiconductor wafer 3 is processed.
If the resin component contained in the sacrificial layer (resin composition) 2 has a temperature at which thermal decomposition occurs due to irradiation with active energy rays, prior to heating the sacrificial layer 2 in the desorption step. Then, the following active energy ray irradiation process may be performed.

(Active energy ray irradiation process)
In this step, the sacrificial layer 2 is irradiated with active energy rays.

  Here, in the case where the resin component has a temperature at which thermal decomposition occurs due to irradiation with active energy rays, the temperature at which thermal decomposition occurs in the presence of an acid or a base in the resin composition decreases. The resin component and an activator that generates an acid or a base upon irradiation with an active energy ray on the temporary fixing agent are included. Therefore, when energy is imparted to the active agent contained in the temporary fixing agent (resin composition), active species such as acid or base are generated from the active agent. The temperature for thermal decomposition decreases.

  Therefore, prior to the heating of the sacrificial layer 2, the sacrificial layer 2 is irradiated with the active energy rays, whereby the heating temperature, the heating time, etc. when heating the sacrificial layer 2 can be reduced or shortened. Therefore, this heating can be performed under more relaxed conditions. As a result, alteration / deterioration due to heating of the semiconductor wafer 3 can be suppressed or prevented more accurately.

  Moreover, it is although it does not specifically limit as an active energy ray, For example, it is preferable that it is a light ray with a wavelength of about 200-800 nm, and it is more preferable that it is a light ray with a wavelength of about 300-500 nm.

Further, the irradiation amount of the active energy ray is not particularly ^limited, but is preferably ^{10mj / cm 2 ~20000mj / cm 2} , and more preferably ^{20mj / cm 2 ~10000mj / cm 2} .

  In addition, even if the resin component has a temperature at which thermal decomposition is caused by irradiation with active energy rays, the sacrificial layer 2 undergoes a thermal history in the processing step because the active energy rays are applied to the sacrificial layer 2. Is before being irradiated. Therefore, for a resin component whose temperature to be thermally decomposed by irradiation with active energy rays is reduced, that is, a resin component whose temperature to be thermally decomposed in the presence of an acid or a base is reduced, a temperature Y at which the resin component is thermally decomposed, A temperature at which the resin component before being irradiated with the active energy ray is thermally decomposed.

<< Second Embodiment >>
Next, 2nd Embodiment of the processing method of the base material of this invention is described.

  FIG. 2 is a plan view of a supporting substrate used in the second embodiment of the processing step for processing a semiconductor wafer.

  Further, the hatching in FIG. 2 is included in the first region 11 in order to show the difference between the first region 11 and the second region 12 in an easy-to-understand manner, and does not indicate a cross section.

  Hereinafter, although 2nd Embodiment of the processing method of a base material is described, it demonstrates centering around difference with 1st Embodiment of the processing method of a base material, and abbreviate | omits the description about the same matter.

  The second embodiment of the substrate processing method is the same as the first embodiment of the substrate processing method except that the configuration of the supporting substrate used in the substrate processing method is different.

  That is, in the present embodiment, the upper surface of the support substrate 1 having a disk shape includes the first region 11 and the second region 12 having different affinity for the temporary fixing agent, and the first region 11 or the first region The affinity for the temporary fixing agent in any one of the two regions 12 is substantially equal to the affinity for the temporary fixing agent of the functional surface 31 of the semiconductor wafer 3.

  Further, in the present embodiment, as shown in FIG. 2, the upper surface (one surface) of the support base 1 is an annular first region 11 along the edge and the center of the first region 11. On the side, the first region 11 and the continuous second region 12 are included.

  As described above, the upper surface of the support substrate 1 has the first region 11 and the second region 12, and the affinity of any of these regions with the temporary fixing agent is determined based on the temporary fixing agent of the functional surface 31. Even when the affinity is set to be substantially equal, the semiconductor wafer 3 and the support base 1 are bonded with excellent adhesion via the sacrificial layer 2, and the sacrificial layer 2 has a uniform film thickness. Therefore, the same effect as described in the first embodiment can be obtained.

  By the way, when the affinity is uniform over the entire upper surface of the support base 1 as in the first embodiment, or when the viscosity of the temporary fixative is relatively low, the temporary fixative is easily supported by the support group. In the sacrificial layer 2 obtained by spreading the upper surface of the material 1, the outer edge thickness tends to be slightly increased. On the other hand, when the viscosity of the temporary fixing agent is relatively high, the temporary fixing agent It is difficult to spread the upper surface, and the obtained sacrificial layer 2 may show a tendency that the thickness of the central portion in the vicinity of the supply start point of the temporary fixing agent and its vicinity is slightly increased.

  As a result, depending on the viscosity of the temporary fixing agent, the distance between the support base 1 and the semiconductor wafer 3 cannot be kept constant, and the entire upper surface of the semiconductor wafer 3 is processed uniformly in the processing steps described above. The processing accuracy of the semiconductor wafer 3 may be reduced.

  Therefore, in the present embodiment, a region having different affinity for the temporary fixing agent is provided on the upper surface of the support base 1 to further improve the thickness uniformity (flatness) of the sacrificial layer 2 to be formed. Thereby, the distance of the support base material 1 and the semiconductor wafer 3 can be hold | maintained uniformly more reliably, and the whole upper surface of the semiconductor wafer 3 can be processed more uniformly.

  More specifically, when the viscosity of the temporary fixing agent is relatively low, the affinity for the temporary fixing agent in the second region is made substantially equal to the affinity for the temporary fixing agent of the functional surface 31, and the first region 11. It is preferable to set so that the affinity of is lower than the affinity of the second region 12. On the other hand, when the viscosity of the temporary fixing agent is relatively high, the affinity for the temporary fixing agent in the first region is made substantially equal to the affinity for the temporary fixing agent of the functional surface 31, and the first It is preferable to set the affinity of the region 11 to be higher than the affinity of the second region 12. Thereby, the thickness of the sacrificial layer 2 can be made more uniform.

  In addition, since the temporary fixing agent can easily spread the upper surface of the support base material 1 by making the first region 11 and the second region 12 continuous as in this embodiment, it is uniform. The sacrificial layer 2 having a sufficient thickness can be formed more reliably.

  In the second embodiment described above, the upper surface of the support base material 1 includes an annular first region 11 along the edge and a second region 12 inside the first region 11. However, the first region and the second region may be spiral.

  Moreover, in each embodiment, although the case where the semiconductor wafer 3 was used as a base material was demonstrated to an example, it is not restricted to such a case, For example, a wiring board, a circuit board, etc. can also be used.

  As mentioned above, although the processing method of the base material of this invention was demonstrated based on embodiment of illustration, this invention is not limited to these.

For example, each constituent material contained in the temporary fixing agent used in the processing method of the base material of the present invention can be replaced with an arbitrary material that can exhibit the same function, or an arbitrary structure is added. can do.
Moreover, the arbitrary process may be added to the processing method of the base material of this invention as needed.

DESCRIPTION OF SYMBOLS 1 Support base material 2 Sacrificial layer 3 Semiconductor wafer 31 Functional surface 11 1st area | region 12 2nd area | region

Claims (15)

A thin film is formed by supplying a temporary fixing agent composed of a resin composition containing a resin component that is melted or vaporized by heating to heat on one surface of the supporting substrate using a spin coating method, and then drying. A first step;
A second step of bonding the substrate and the support substrate through the thin film;
A third step of processing the surface of the substrate opposite to the supporting substrate;
A fourth step of desorbing the base material from the support base material by thermally decomposing the resin component by heating the thin film;
At least a part of the one surface of the support base has an affinity for the temporary fixing agent that is substantially equal to the affinity of the surface of the base on the side of the support base for the temporary fixing agent. A substrate processing method characterized by being set.   The base material according to claim 1, wherein the affinity of the one surface with respect to the temporary fixing agent is adjusted by at least one of setting of a surface roughness Ra of the one surface and surface treatment on the one surface. Processing method.   The one surface of the support base includes a first region and a second region that have different affinity for the temporary fixing agent, and is in either the first region or the second region. The substrate processing method according to claim 1 or 2, wherein the affinity for the temporary fixing agent is substantially equal to the affinity for the temporary fixing agent on the surface of the substrate on the side of the supporting substrate.   The said 1st area | region is an area | region along the edge part of the said one surface of the said support base material, The said 2nd area | region is an area | region inside the said 1st area | region. Substrate processing method.   The substrate processing method according to claim 3 or 4, wherein the first region and the second region are continuous regions.   The substrate processing method according to claim 1, wherein in the first step, the thin film is formed to have an average thickness of 50 to 100 μm.   The substrate processing method according to claim 1, wherein in the first step, the thin film having a TMA softening point of less than 200 ° C. is formed.   The said 2nd process WHEREIN: It pressurizes with the pressure of 0.01-3 Mpa in the direction in which the said base material and the said support base material mutually approach in the state which interposed the said thin film. Processing method of the substrate.   The substrate processing method according to any one of claims 1 to 8, wherein in the second step, the thin film is heated at a temperature of 100 to 300 ° C.   The substrate processing method according to claim 9, wherein the time for heating the thin film is 0.1 to 10 minutes.   The resin component is such that the thermal decomposition temperature is lowered by irradiation of active energy rays to the temporary fixing agent, and the thin film is irradiated with the active energy rays prior to the fourth step. Item 11. A method for processing a substrate according to any one of Items 1 to 10.   The resin component is such that the temperature at which the thermal decomposition occurs in the presence of an acid or a base decreases, and the resin composition further contains an activator that generates an acid or a base upon irradiation with the active energy ray. Item 12. A method for processing a substrate according to Item 11.   The substrate processing method according to claim 11 or 12, wherein the resin component is a polycarbonate-based resin.   The method for processing a substrate according to any one of claims 1 to 10, wherein the resin component does not lower the temperature at which the thermal decomposition is caused by irradiation of the temporary fixing agent with active energy rays.   The substrate processing method according to claim 14, wherein the resin component is a norbornene-based resin.

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